<!doctype html>
<!--
Copyright 2018 The Immersive Web Community Group

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-->
<html>
  <head>
    <meta charset='utf-8'>
    <meta name='viewport' content='width=device-width, initial-scale=1, user-scalable=no'>
    <meta name='mobile-web-app-capable' content='yes'>
    <meta name='apple-mobile-web-app-capable' content='yes'>

    <!-- Origin Trial Token, feature = WebXR Device API, origin = https://immersive-web.github.io, expires = 2018-08-28 -->
<meta http-equiv="origin-trial" data-feature="WebXR Device API" data-expires="2018-08-28" content="AnNpu7ceXvLew05ccD8Zr1OZsdZiB2hLQKK82kTTMDwF7oRKtP3QEJ4RzkeHrmB8Sq0vSV6ZNmszpBCZ0I8p9gAAAABceyJvcmlnaW4iOiJodHRwczovL2ltbWVyc2l2ZS13ZWIuZ2l0aHViLmlvOjQ0MyIsImZlYXR1cmUiOiJXZWJYUkRldmljZSIsImV4cGlyeSI6MTUzNTQxNDQwMH0=">

    <title>AR Local Space and Anchor test</title>

    <link href='../css/common.css' rel='stylesheet'></link>

    <!--The polyfill is not needed for browser that have native API support,
        but is linked by these samples for wider compatibility.-->
    <!--script src='https://cdn.jsdelivr.net/npm/webxr-polyfill@latest/build/webxr-polyfill.js'></script-->
    <script src='../js/xrray-polyfill.js' type='module'></script>
    <script src='../js/webxr-polyfill.js'></script>

    <script src='../js/webxr-button.js'></script>
  </head>
  <body>
    <header>
      <details open>
        <summary>AR Local Space and Anchor test</summary>
        This sample places an anchor at local origin at session creation
        to help visualise local space drift compared to an anchor.
        <p>
          <input id="useDomOverlay" type="checkbox" checked style="visibility: hidden;">
          <!-- <label for="useDomOverlay">Enable DOM Overlay</label><br/> -->

          <a class="back" href="./index.html">Back</a>
        </p>
        <p>
          Viewer pose emulated? <span id="viewer_pose">No viewer pose yet.</span><br/>
          Anchor position=<span id="anchor_pose">No anchor placed yet.</span><br/>
          Anchor drift=<span id="anchor_drift">No anchor placed yet.</span>
        </p>
      </details>
    </header>
    <script type="module">
      import {Scene} from '../js/cottontail/src/scenes/scene.js';
      import {Renderer, createWebGLContext} from '../js/cottontail/src/core/renderer.js';
      import {Gltf2Node} from '../js/cottontail/src/nodes/gltf2.js';
      import {RayNode} from '../js/cottontail/src/nodes/ray-node.js';
      import {QueryArgs} from '../js/cottontail/src/util/query-args.js';
      import {FallbackHelper} from '../js/cottontail/src/util/fallback-helper.js';
      import {Node} from '../js/cottontail/src/core/node.js';
      import {vec3, vec4, quat} from '../js/cottontail/src/math/gl-matrix.js';
      import {DebugSources} from '../js/debug-sources.js';

      // If requested, initialize the WebXR polyfill
      if (QueryArgs.getBool('allowPolyfill', false)) {
        var polyfill = new WebXRPolyfill();
      }

      let debugSources;
      if (QueryArgs.getBool('debugSources', false)) {
        debugSources = new DebugSources();
      }

      const useDomOverlay = document.getElementById('useDomOverlay');

      const viewerPoseEmulatedElement = document.getElementById('viewer_pose');
      const anchorPoseElement = document.getElementById('anchor_pose');
      const anchorDriftElement = document.getElementById('anchor_drift');

      // Debugging constants:
      const visualizeObjectSpace = true;

      // Suppress XR events for interactions with the DOM overlay
      document.querySelector('header').addEventListener('beforexrselect', (ev) => {
        console.log(ev.type);
        ev.preventDefault();
      });

      // XR globals.
      let xrButton = null;
      let xrRefSpace = null;
      let xrViewerSpace = null;
      let xrViewerOffsetSpace = null;
      let xrAnchor = null;

      // WebGL scene globals.
      let gl = null;
      let renderer = null;
      let scene = new Scene();
      scene.enableStats(false);

      // Visualise the origin.
      {
        let xRay = new RayNode({direction : [5, 0, 0], baseColor : [1, 0, 0, 1]});
        let yRay = new RayNode({direction : [0, 5, 0], baseColor : [0, 1, 0, 1]});
        let zRay = new RayNode({direction : [0, 0, 5], baseColor : [0, 0, 1, 1]});

        scene.addNode(xRay);
        scene.addNode(yRay);
        scene.addNode(zRay);
      }

      // Add node with flower object (no shadow):
      let arObject = new Node();
      arObject.visible = false;
      scene.addNode(arObject);

      let flower = new Gltf2Node({url: '../../media/gltf/sunflower/sunflower.gltf'});
      arObject.addNode(flower);

      const MAX_FLOWERS = 30;
      let flowers = [];

      // Ensure the background is transparent for AR.
      scene.clear = false;

      function initXR() {
        xrButton = new XRDeviceButton({
          onRequestSession: onRequestSession,
          onEndSession: onEndSession,
          textEnterXRTitle: "START AR",
          textXRNotFoundTitle: "AR NOT FOUND",
          textExitXRTitle: "EXIT  AR",
          supportedSessionTypes: ['immersive-ar'],
          height: 36,
        });
        document.querySelector('header').appendChild(xrButton.domElement);
      }

      function onRequestSession() {
        let sessionInit = {
          requiredFeatures: ['anchors'],
          optionalFeatures: [],
        };
        if (useDomOverlay.checked) {
          sessionInit.optionalFeatures.push('dom-overlay');
          sessionInit.domOverlay = {root: document.body};
        }
        navigator.xr.requestSession('immersive-ar', sessionInit).then((session) => {
          session.mode = 'immersive-ar';
          xrButton.setSession(session);
          onSessionStarted(session);
        });
      }

      function onSessionStarted(session) {
        useDomOverlay.disabled = true;
        session.addEventListener('end', onSessionEnded);
        session.addEventListener('select', onSelect);

        if (debugSources) debugSources.startSession(session);

        if (!gl) {
          gl = createWebGLContext({
            xrCompatible: true,
            alpha : true,
          });

          renderer = new Renderer(gl);
          gl.lineWidth(5);

          scene.setRenderer(renderer);
        }

        session.updateRenderState({
            baseLayer: new XRWebGLLayer(session, gl)
        });

        Promise.all([
          session.requestReferenceSpace('local'),
          session.requestReferenceSpace('viewer')
        ]).then(([localSpace, viewerSpace]) => {
          xrRefSpace = localSpace;
          xrViewerSpace = viewerSpace;

          xrViewerOffsetSpace = xrViewerSpace.getOffsetReferenceSpace(new XRRigidTransform(
            {z: -1}
          ));

          session.requestAnimationFrame(onXRFrame);
        });
      }

      function onEndSession(session) {
        session.end();
      }

      function onSessionEnded(event) {
        useDomOverlay.disabled = false;
        xrButton.setSession(null);
      }

      // Attaches a scene node at anchor location. The scene node will not have any associated
      // models with it, just the 3 axes to visualize the anchor's coordinate system.
      function onCreateAnchor(anchor) {
        console.debug("Anchor created");

        anchor.context = {};

        let sceneObject = new Node();
        sceneObject.visible = false;

        let xRay = new RayNode({direction : [5, 0, 0], baseColor : [1, 1, 0, 1]});
        let yRay = new RayNode({direction : [0, 5, 0], baseColor : [0, 1, 1, 1]});
        let zRay = new RayNode({direction : [0, 0, 5], baseColor : [1, 0, 1, 1]});

        sceneObject.addNode(xRay);
        sceneObject.addNode(yRay);
        sceneObject.addNode(zRay);

        scene.addNode(sceneObject);

        anchor.context.sceneObject = sceneObject;
        sceneObject.anchor = anchor;
      }

      // Attaches a scene node at anchor location. The placed scene node will have a flower
      // model associated with it. Optionally, depending on the value of |visualizeObjectSpace|,
      // the scene node will also have 3 axes attached to visualize the coordinate system.
      function onCreateAnchorWithFlower(anchor) {
        console.debug("Anchor created, placing flower.");

        anchor.context = {};

        let sceneObject = arObject.clone();
        sceneObject.visible = false;

        if (visualizeObjectSpace) {
          let xRay = new RayNode({direction : [5, 0, 0], baseColor : [1, 0, 0, 1]});
          let yRay = new RayNode({direction : [0, 5, 0], baseColor : [0, 1, 0, 1]});
          let zRay = new RayNode({direction : [0, 0, 5], baseColor : [0, 0, 1, 1]});

          sceneObject.addNode(xRay);
          sceneObject.addNode(yRay);
          sceneObject.addNode(zRay);
        }

        scene.addNode(sceneObject);
        flowers.push(sceneObject);

        anchor.context.sceneObject = sceneObject;
        sceneObject.anchor = anchor;

        // For performance reasons if we add too many objects start
        // removing the oldest ones to keep the scene complexity
        // from growing too much.
        if (flowers.length > MAX_FLOWERS) {
          let oldFlower = flowers.shift();
          oldFlower.anchor.delete();
          scene.removeNode(oldFlower);
        }
      }

      let anchorRequesed = false;
      let anchorRemoved = false;

      function onSelect(event) {
        const frame = event.frame;

        frame.createAnchor(new XRRigidTransform(), xrViewerOffsetSpace)
              .then(onCreateAnchorWithFlower);
      }

      function getAngle(a, b) {
        let dotproduct = quat.dot(a, b);
        return Math.acos(2 * dotproduct * dotproduct - 1);
      }

      // Set with all anchors tracked in a previous frame.
      let all_previous_anchors = new Set();

      // Called every time a XRSession requests that a new frame be drawn.
      async function onXRFrame(t, frame) {
        let session = frame.session;
        session.requestAnimationFrame(onXRFrame);

        if (debugSources) debugSources.update(frame, xrRefSpace);

        let pose = frame.getViewerPose(xrRefSpace);
        if(pose) {
          viewerPoseEmulatedElement.innerText = pose.emulatedPosition.toString();
        } else {
          viewerPoseEmulatedElement.innerText = "Viewer pose is null.";
        }

        let offsetSpacePose = frame.getPose(xrViewerOffsetSpace, xrRefSpace);
        if(offsetSpacePose) {
          arObject.visible = true;
          arObject.matrix = offsetSpacePose.transform.matrix;
        } else {
          arObject.visible = false;
        }

        if(!anchorRequesed) {
          // Initial anchor creation.
          frame.createAnchor(new XRRigidTransform(), xrRefSpace)
               .then((anchor) => {
                  console.debug("Anchor created.");
                  xrAnchor = anchor;
                  onCreateAnchor(anchor);
               })
               .catch((error) => {
                  console.error("Anchor failed to create.");
                  anchorRequesed = false;
               });

          anchorRequesed = true;
        }

        const tracked_anchors = frame.trackedAnchors;

        if(tracked_anchors){
          all_previous_anchors.forEach(anchor => {
            if(!tracked_anchors.has(anchor)){
              scene.removeNode(anchor.context.sceneObject);
              if(anchor === xrAnchor) {
                anchorRemoved = true;
                console.debug("Anchor removed.");
              }
            }
          });

          tracked_anchors.forEach(anchor => {
            const anchorPose = frame.getPose(anchor.anchorSpace, xrRefSpace);
            if(anchorPose) {
              anchor.context.sceneObject.matrix = anchorPose.transform.matrix;
              anchor.context.sceneObject.visible = true;
            } else {
              anchor.context.sceneObject.visible = false;
            }
          });

          all_previous_anchors = tracked_anchors;
        } else {
          all_previous_anchors.forEach(anchor => {
            scene.removeNode(anchor.sceneObject);
          });

          all_previous_anchors = new Set();
        }

        if (xrAnchor) {
          const anchorPose = frame.getPose(xrAnchor.anchorSpace, xrRefSpace);
          if (anchorPose) {
            const pos = anchorPose.transform.position;
            const rot = anchorPose.transform.orientation;

            const degs = getAngle(
              quat.fromValues(rot.x, rot.y, rot.z, rot.w),
              quat.create()
            ) * 180 / Math.PI;

            anchorPoseElement.innerText = pos.x.toFixed(3) + "m,"
                                        + pos.y.toFixed(3) + "m,"
                                        + pos.z.toFixed(3) + "m,"
                                        + degs.toFixed(3) + "deg";

            const drift = Math.sqrt(pos.x * pos.x + pos.y * pos.y + pos.z * pos.z);
            anchorDriftElement.innerText = drift.toFixed(3) + "m";

            console.debug(pos, rot, drift);
          } else {
            anchorPoseElement.innerText = "Anchor pose null.";
            anchorDriftElement.innerText  = "Anchor pose null.";
          }
        } else if(anchorRemoved) {
          anchorPoseElement.innerText = "Anchor already gone.";
          anchorDriftElement.innerText  = "Anchor already gone.";
        }
        else {
          anchorPoseElement.innerText = "Anchor not created yet.";
          anchorDriftElement.innerText  = "Anchor not created yet.";
        }

        await scene.waitForComplete();

        scene.startFrame();
        scene.drawXRFrame(frame, pose);
        scene.endFrame();
      }

      // Start the XR application.
      initXR();
    </script>
  </body>
</html>
